$('.carousel').carousel({
  interval: 3000
})
let overArray = document.getElementsByClassName('over')
for(let i =0 ; i < overArray.length ; i ++){
  overArray[i].onmouseenter=function(){
    this.style.backgroundSize = '150%';
    this.style.transition = 'all 1s';
  }
   overArray[i].onmouseleave=function(){
    this.style.backgroundSize = '100%';
  }
}